1. Field of Invention
The present invention relates to a center pillar outer and a manufacturing method thereof which can improve side collision performance of a vehicle.
2. Description of Related Art
When a protruding portion of a barrier with a rigid body collides with a lower portion of a center pillar of a side body in a vehicle side collision test, a serious fracture occurs in the center pillar, based on a barrier hitting portion (a section of the center pillar, where the protruding portion of the barrier directly hits the center pillar).
In order to overcome such a serious fracture, a hot stamping method has been conventionally used in manufacturing of a panel component such as a center pillar. The hot stamping method is a method of producing a high-strength component by heating a material such as an iron plate at a high temperature, molding the heated material using a press and rapidly cooling the pressed material. The hot stamping method can produce a rigid and light component, as compared with the existing molding method of producing a panel component by pressing a material at a normal temperature.
FIG. 1 is a view schematically showing the structure of a side body to which a conventional center pillar outer for a vehicle is applied. As shown in FIG. 1, the center pillar outer 10 is attached between a side outer panel 210 and a side inner panel 220 of the vehicle, and a hinge bracket 20 for reinforcing the strength of a portion at which a door hinge is assembled with the center pillar outer 10 is attached to an inside of the center pillar outer 10.
When a one-piece type panel component such as the conventional center pillar outer 10 is, the component is locally softened by applying the hot stamping method in order to improve collision performance. Accordingly, one component having the same thickness has partially different strengths.
FIG. 2 is a view showing a conventional center pillar outer manufactured using a hot stamping method. The center pillar outer 10 shown in FIG. 2 is molded using the hot stamping method so that the strength of its lower end portion is relatively weakened as compared with that of its upper end portion. Conventionally, the center pillar outer 10 was used in a center pillar of a vehicle side body to guide deformation of the center pillar in the side collision of a vehicle, thereby preventing a fracture of the center pillar.
A mold for hot stamping is designed and used to manufacture a panel component such as a center pillar outer molded by being locally softened as described above. In this case, it takes a long time to develop the mold for hot stamping, and hence the mold investment cost (initial investment costs) for the mold is excessively increased. Since the durability of the mold is weak, spare molds are additionally required.
The information disclosed in this Background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.